Field of the Invention
The present invention relates to a water jacket for an engine. More particularly, the present invention relates to a water jacket for an engine, which can improve entire cooling efficiency by controlling a flow of a coolant.
Description of Related Art
In general, a part of heat generated from a combustion chamber of an engine is absorbed by a cylinder heat, a cylinder block, intake/exhaust valves, and a piston.
When a temperature is excessively increased, the constituent parts may undergo thermal deformation or an oil film in an inner wall of the cylinder may be damaged such that lubrication failure may be caused, thereby causing and a thermal defect.
Such a thermal defect may cause abnormal combustion such as combustion failure, knocking, and the like, thereby causing serious damage such as melting of the piston. In addition, thermal efficiency and output may be deteriorated. On the contrary, excessive cooling of the engine may cause deterioration of an output and fuel consumption efficiency and low-temperature abrasion of the cylinder, and accordingly, a temperature of the coolant should be appropriately controlled.
In such an aspect, a water jacket is provided in the inside of a cylinder block and a cylinder head of a conventional engine, and a coolant circulating the water jacket cools metal surfaces such as the periphery of a spark plug that corresponds to the combustion chamber, an exhaust port, and the periphery of a valve sheet.
However, in the water jacket applied to the cylinder block and the cylinder head of the conventional engine, the coolant sequentially introduced into each cylinder is respectively circulated such that the cylinder block and the cylinder head corresponding to the combustion chamber cannot be effectively cooled, and accordingly, the entire engine canoe be effectively cooled.
In addition, sine the engine cannot be effectively cooled, durability of the engine is deteriorated, and thus an additional cooling jet needs to be installed to prevent the deterioration of the durability or performance of the water pump needs to be improved, thereby causing increase of investment cost.
Further, the cylinder head needs to be cooled down to a temperature that is relatively lower than that of the cylinder block, but it is difficult to respectively control temperatures of the coolant.
In addition, when a temperature of the coolant is low, viscosity of oil is increased so that a frictional force is increased, which causes increase of fuel consumption, thereby causing deterioration of fuel consumption efficiency, and when a temperature of the coolant of the engine is excessively high, knocking is generated, which causes control of ignition timing, thereby causing deterioration of engine performed.
The information disclosed in this Background of the Invention section is only for enhancement of understanding of the general background of the invention and should not be taken as an acknowledgement or any form of suggestion that this information forms the prior art already known to a person skilled in the art.